Persistent pain, sufficient to cause significant impairment in daily functioning, affects up to 50 percent of older adults. Analgesics are the most common therapy used to manage pain, with opioids playing an increasingly important role in the pharmacological treatment of chronic disabling pain in older adults. The efficacy of opioid therapy needs to be balanced against potential side effects, including the risk of neurocognitive impairment. To date, no studies have examined the effects of opioids on the neurocognitive function of older adults. The proposed study will measure the objective and subjective neurocognitive effects of oxycodone in healthy older (>65 years) adults. Because older adults may evidence a different pattern of response to opioid medication than younger adults, we will also measure objective and subjective neurocognitive effects of oxycodone in a healthy middle age (35-55 years of age) population. In this manner we will be able to systematically examine aging effects using cross sectional methodology. We will also characterize the pharmacokinetics of a dose level of oxycodone in a sample of middle age and older adults. This study focuses on priority research areas for the NIA, those of pain management and cognitive impairment. Moreover, it addresses an important but understudied area in the treatment of persistent pain. Much of the research on opioid use for persistent pain has not included older adults and the examination of neurocognitive effects in elders is lacking. This project is well suited for the R21 mechansim as the project will establish the feasability of administring a specific level of opiod medication to a group of healthy older adults. Results of this feasability project will provide important preliminary data and background information for subsequent opiod dose response studies in the laboratory as well as neuorcognitive and side effect characterization of opioids in a clinical sample of older adults with persistent pain.